Vibration Control Mount Apparatus

ABSTRACT

A vibration control mount apparatus capable of absorbing an initial pushing-up load based on a shock and capable of promptly damping a residual vibration generated after the shock. The vibration control mount apparatus includes a case body mounted on a turning frame, a mount rubber is mounted on the case body. A magnetic viscous fluid of which viscosity is changed by a magnetic filed is sealed in a sealing chamber in the case body. A movable body supported by the mount rubber has a damper plate which moves while receiving resistance from the magnetic viscous fluid in the sealing chamber. Viscosity variable controlling device forms the magnetic field in accordance with vibration acceleration detected by the acceleration detecting device to change the viscosity of the magnetic viscous fluid.

CROSS REFERENCE TO PRIOR APPLICATION

This application is a U.S. national phase application under 35 U.S.C.§371 of International Patent Application No. PCT/JP2005/012797, filedJul. 12, 2005, and claims the benefit of Japanese Application No.2005/061544, filed Mar. 4, 2005. The International Application has notpublished yet at the time of filing of this application.

TECHNICAL FIELD

The present invention relates to a vibration control mount apparatuscapable of absorbing an initial pushing-up load based on a shock andcapable of promptly damping a residual vibration generated after theshock.

BACKGROUND ART

Conventionally, for example, a vibration control mount apparatus such asa viscous mount has been known. The viscous mount including: a case bodymounted on a mount base member such as a frame of a truck; an elasticbody mounted on the case body; a sealing chamber formed in the casebody; damping liquid such as silicon oil sealed in the sealing chamber;a movable body that has a damper plate which moves while receivingresistance from the damping liquid in the case body, that is supportedby the elastic body and on which a cab floor member is mounted; and agap (orifice) formed between an outer circumference of the damper plateand an inner circumference of the case body. (e.g. see JapaneseLaid-open Patent Publication No. 7-133841)

DISCLOSURE OF THE INVENTION

However, in the above-described conventional vibration control mountapparatus, for example, when a gap (orifice) between the damper plateand the case body is made smaller so that a residual vibration, which isgenerated after a shock such as a pushing-up load is applied, ispromptly damped, an initial pushing-up load cannot be absorbed when theshock is applied. As a result, large force is applied to a cab floormember side, and there is a possibility of causing reduction indurability of the cab, etc. On the other hand, when the gap (orifice) ismade larger, there is a problem such that the residual vibration remainsfor a long period of time. In view of such problems, the presentinvention has been carried out, and it is an object of the presentinvention to provide a vibration control mount apparatus capable ofabsorbing the initial pushing-up load based on a shock and capable ofpromptly damping the residual vibration generated after the shock.

Device for Solving Problems

A vibration control mount apparatus includes a case body mounted on amount base member; an elastic body mounted on the case body; a sealingchamber formed in the case body and a viscosity change fluid which issealed in the sealing chamber and of which viscosity is changed. Furtherincluding a movable body having a damper portion, which moves whilereceiving resistance from the viscosity change fluid in the sealingchamber, and is supported by the elastic body; an acceleration detectingdevice for detecting vibration acceleration of the movable body; andviscosity variable controlling device for changing the viscosity of theviscosity change fluid in accordance with the vibration accelerationdetected by the acceleration detecting device.

The vibration control mount apparatus can absorb an initial pushing-upload based on a shock and promptly damp a residual vibration generatedafter the shock.

In another embodiment of a vibration control mount apparatus theviscosity change fluid of the vibration control mount apparatuscorresponds to a magnetic viscous fluid of which viscosity is changed bya magnetic field, and the viscosity variable controlling device formsthe magnetic field in accordance with the vibration accelerationdetected by the acceleration detecting device to change the viscosity ofthe magnetic viscous fluid.

The vibration control mount apparatus according to the above canproperly absorb the initial pushing-up load based on a shock andproperly and promptly damp the residual vibration generated after theshock with use of the magnetic viscous fluid of which viscosity ischanged by the magnetic field.

The viscosity change fluid of the vibration control mount apparatuscorresponds to an electric viscous fluid of which viscosity is changedby application of voltage, and the viscosity variable controlling deviceapplies voltage in accordance with vibration acceleration detected bythe acceleration detecting device to change the viscosity of theelectric viscous fluid.

The vibration control mount apparatus can properly absorb the initialpushing-up load based on a shock and properly and promptly damp theresidual vibration generated after the shock with use of the electricviscous fluid of which viscosity is changed by application of voltage.

In an embodiment the viscosity variable controlling means of thevibration control mount apparatus raises the viscosity of the viscositychange fluid during the residual vibration generated after the shock.

The vibration control mount can also properly and promptly damp theresidual vibration by raising the viscosity of the viscosity changefluid during the residual vibration generated after the shock.

In a vibration control mount apparatus according to any of the aboveembodiments the mount base member of the vibration control mountapparatus corresponds to a turning frame of a working machine, and a cabfloor member is mounted on the movable body.

Further, in a vibration control mount apparatus, an excellent vibrationcontrol effect to the cab floor member is exerted, and durability of thecab and riding comfort of an operator, etc., are improved.

Effects of the Invention

According to the invention, it is possible to absorb an initialpushing-up load based on a shock and possible to promptly damp aresidual vibration generated after the shock.

According to another aspect of the invention, it is possible to properlyabsorb the initial pushing-up load based on a shock and possible toproperly and promptly damp the residual vibration generated after theshock with use of a magnetic viscous fluid of which viscosity is changedby a magnetic field. According to the invention, it is possible toproperly absorb the initial pushing-up load based on a shock andpossible to properly and promptly damp the residual vibration generatedafter the shock with use of an electric viscous fluid of which viscosityis changed by application of voltage.

According to an embodiment, the invention, it is possible to properlyand promptly damp the residual vibration by raising the viscosity of aviscosity change fluid during the residual vibration generated after theshock.

According to the invention, it is possible to exert an excellentvibration control effect to a cab floor member and possible to planimprovements in durability of the cab and riding comfort of an operator,etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a constitutional diagram showing an embodiment of a vibrationcontrol mount apparatus of the present invention;

FIG. 2 is a cross sectional view of the vibration control mountapparatus of the present invention;

FIG. 3 is a side view of an oil hydraulic power shovel provided with thevibration control mount apparatus of the present invention;

FIG. 4 is a schematic view of the vibration control mount apparatus ofthe present invention;

FIG. 5 is a graph indicating force F applied to a cab floor member and aspeed dx/dt of a turning frame;

FIG. 6 is a graph indicating a damping factor C of the vibration controlmount apparatus of the present invention; and

FIG. 7 is a constitutional diagram showing another embodiment of thevibration control mount apparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be explained with reference tothe accompanying drawings.

In FIG. 3, reference symbol 1 denotes an oil hydraulic power shovel as aworking machine, the oil hydraulic power shovel 1 includes a lowerportion traveling body 2 of a crawler type, and a substantiallyplate-shaped turning frame 3 as a mount base member is provided abovethe lower portion traveling body 2 via a turning bearing portion 4 to beturnable around an axis of a vertical direction (not shown). Moreover, abody 7 is constituted by the lower portion traveling body 2, the turningbearing portion 4 and the turning frame 3.

Further, on the turning frame 3 of the body 7, a working apparatus 5which performs digging work and a power apparatus 6 constituted by anengine and a oil hydraulic pump driven by the engine, etc., areprovided. Furthermore, as shown in FIG. 1 and FIG. 2, a substantiallyplate-shaped cab floor member 9 of a cab 8 is provided above the turningframe 3 via the plurality of, for example, four vibration control mountapparatuses 10 such as viscous mounts.

The vibration control mount apparatus 10 includes a bottomedsubstantially cylindrical case body 11 mounted on the turning frame 3,for example, the case body 11 is constituted by an outer cylinder member12 and an intermediate cylinder member 13. A mount rubber 14, which issubstantially cylindrical and an upper and lower surface opening-shapedelastic body, is mounted on the case body 11. A sealing chamber 15 isformed in the case body 11, a magnetic viscous fluid 16, of whichviscosity is changed by a magnetic field and which is a liquid viscositychange fluid, is sealed in the sealing chamber 15. Moreover, when themagnetic viscous fluid (magnetic fluid) 16 such as silicon oilincluding, for example, a magnetic particle and a surface active agentis placed in the magnetic field, an apparent viscosity is raised.

Further, the vibration control mount apparatus 10 includes a movablebody 21 which is movably supported by the mount rubber 14 based on anelastic deformation of the mount rubber 14 and on which the cab floormember 9 is mounted by a bolt 20. For example, the movable body 21 isconstituted by a guide shaft 22 such as a center pin, which is fittedand inserted into an inner circumference side of the mount rubber 14 andin which the bolt 20 is screw-engaged with an upper portion of thecenter pin, and a damper plate 23 as a substantially disc-shaped damperportion which is mounted on a lower end of the guide shaft 22 and whichmoves while receiving resistance from the magnetic viscous fluid 16 inthe sealing chamber 15. A circle ring-shaped gap (orifice) 24 is formedbetween an outer circumference surface of the damper plate 23 and aninner circumference surface of the outer cylinder member 12 of the casebody 11.

Further, the vibration control mount apparatus 10 includes accelerationdetecting device 31 for detecting vibration acceleration of the movablebody 21. For example, the acceleration detecting device 31 is anacceleration sensor for detecting vibration acceleration of the cab 8which vibrates in an integrated manner with the movable body 21 in avertical direction.

Furthermore, the vibration control mount apparatus 10 includes viscosityvariable controlling device 32 for forming the magnetic field inaccordance with the vibration acceleration detected by the accelerationdetecting device 31 and for changing viscosity of the magnetic viscousfluid 16 in the sealing chamber 15. The viscosity variable controllingdevice 32 has an integral circuit 32 a, a band-pass filter circuit 32 b,a gain circuit 32 c, an absolute value circuit 32 d, an amplifiercircuit 32 e and an electromagnet 34.

For example, the viscosity variable controlling device 32 forms themagnetic field by turning on of the electromagnet (magnetic fieldforming device) 34, places the magnetic viscous fluid 16 in the sealingchamber 15 in the magnetic field and raises the viscosity of themagnetic viscous fluid 16, only when vibration acceleration near aresonance point frequency between the turning frame 3 and the cab floormember 9 is not less than a predetermined value. An impulse-like shockacceleration of an initial shock is generally a high frequency andfiltered by the band-pass filter circuit 32 b, and therefore a magneticfield is not formed in the initial shock, the viscosity of the magneticviscous fluid 16 remains low. Moreover, it is possible to employ aconstitution in which iron powder, etc., is not concentrated to aperiphery of the electromagnet 34 from the exterior or the outside by aproper sealing mechanism.

Further, for example, when a shock such as a pushing-up load from asurface of bedrock is applied to the body 7 of the oil hydraulic powershovel 1 during digging work by use of the oil hydraulic power shovel 1provided with the vibration control mount apparatus 10, the shockapplied to the body 7 is absorbed by the vibration control mountapparatus 10, and vibration to the cab 8 is controlled.

That is, in the initial shock, the electromagnet 34 remains off, amagnetic field is not formed, and the viscosity of the magnetic viscousfluid 16 remains low. Therefore, an orifice resistance during the fluidmovement in the gap (orifice) 24 becomes smaller, an initial pushing-upload with a large amplitude is absorbed, as a result, a large force isnot applied to the cab floor member 9, and there is no possibility ofcausing a reduction in durability of the cab 8.

Further, after a shock is applied to the body 7 of the oil hydraulicpower shovel 1, when the vibration acceleration near the resonance pointfrequency between the turning frame 3 of the body 7 and the cab floormember 9 of the cab 8 is not less than the predetermined value, currentis supplied to the electromagnet 34, the magnetic field is formed, andthe viscosity of the magnetic viscous fluid 16 in the sealing chamber 15is raised. Therefore, the orifice resistance during the fluid movementin the gap (orifice) 24 becomes larger, a residual vibration with asmall amplitude is promptly damped, as a result, there is no possibilityof causing a reduction in riding comfort of an operator.

The above-described vibration control mount apparatus 10 thus maintainsthe low viscosity of the magnetic viscous fluid 16 without changing itduring the initial pushing-up load based on a shock to absorb the load.The viscosity variable controlling device 32, which raises the viscosityof the magnetic viscous fluid 16 during the residual vibration after theshock, promptly damps the residual vibration based on inertia generatedafter the shock, without a large change to the conventional viscousmount shape. Accordingly, it is possible to plan improvements in thedurability of the cab 8 and the riding comfort of the operator, etc.

Further, the vibration control mount apparatus 10 can change the orificeresistance in the gap (orifice) 24 by the magnetic viscous fluid 16 toenlarge the gap (orifice) 24 between the damper plate 23 and the casebody 11. Therefore, the vibration control mount apparatus 10 can controlabrasion caused by interference between the damper plate 23 and the casebody 11, maintain a stable damping factor characteristic, and make asecular change of performance smaller.

Here, FIG. 4 is a schematic view of the vibration control mountapparatus 10, FIG. 5 is a graph indicating force F applied to a cabfloor member 9 and a speed dx/dt of a turning frame (mount base member)3, and FIG. 6 is a graph indicating a damping factor C of the vibrationcontrol mount apparatus 10.

The force F applied to the cab floor member 9 is represented by theexpression (1) in FIG. 4. In this expression (1), displacement of theturning frame 3 is defined as x, displacement of the cab floor member 9is defined as y, time is defined as t, a spring coefficient of the mountrubber 14 is defined as k and the damping factor is defined as C.Further, when C is changed as shown in FIG. 6, F becomes stable asundulation of the dotted line is extremely small in FIG. 5, andtherefore the durability of the cab 8 and the riding comfort of theoperator, etc., can be improved.

FIG. 7 is a constitutional diagram showing another embodiment of thevibration control mount apparatus 10.

In a vibration control mount apparatus 10 shown in FIG. 7, differingfrom the vibration control mount apparatus as shown in FIG. 1, anelectric viscous fluid 41 as a liquid viscosity change fluid of whichviscosity is changed by application of voltage is sealed in the sealingchamber 15. Moreover, when voltage is applied to the electric viscousfluid (ER fluid) 41, inner particles aggregate to form a chain structurealong an electric field direction, and therefore an apparent viscosityis raised.

Further, the vibration control mount apparatus 10 includes viscosityvariable controlling device 42 for changing the viscosity of theelectric viscous fluid 41 in the sealing chamber 15 by application ofvoltage in accordance with the vibration acceleration detected by theacceleration detecting device 31. The viscosity variable controllingdevice 42 has an integral circuit 42 a, a band-pass filter circuit 42 b,a gain circuit 42 c, an absolute value circuit 42 d and an amplifiercircuit 42 e.

For example, the viscosity variable controlling device 42 appliesvoltage to the bolt 20, the movable body 21, the electric viscous fluid41 and the case body 11 to raise the viscosity of the electric viscousfluid 41 in the sealing chamber 15, only when the vibration accelerationnear the resonance point frequency between the turning frame 3 and thecab floor member 9 is not less than the predetermined value. Theimpulse-like vibration acceleration of the initial shock is generally ahigh frequency and filtered by the band-pass filter circuit 42 b, andtherefore voltage is not applied, the viscosity of the electric viscousfluid 41 remains low.

Moreover, an insulator 43 is provided between the bolt 20 and the capfloor member 9, and a ground 44 is connected to the case body 11. Otherconstitutions of the vibration control mount apparatus 10 shown in FIG.7 are basically similar to the constitutions shown in FIG. 1.

Further, for example, when a shock such as a pushing-up load from asurface of bedrock is applied to the body 7 of the oil hydraulic powershovel 1 during digging work by use of the oil hydraulic power shovel 1provided with the vibration control mount apparatus 10 shown in FIG. 7,the shock applied to the body 7 is absorbed by the vibration controlmount apparatus 10, and the vibration of the cab 8 is controlled. Thatis, the voltage is not applied in the initial shock, the viscosity ofthe electric viscous fluid 41 remains low. Therefore, the orificeresistance during the fluid movement in the gap (orifice) 24 becomessmaller, the initial pushing-up load with the large amplitude isabsorbed, as a result, a large force is not applied to the cab floormember 9, and there is no possibility of causing reduction in thedurability of the cab 8. Furthermore, after the shock is applied to thebody 7 of the oil hydraulic power shovel 1, when the vibrationacceleration near the resonance point frequency between the turningframe 3 of the body 7 and the cab floor member 9 of the cab 8 is notless than the predetermined value, voltage is applied to the electricviscous fluid 41, etc., and the viscosity of the electric viscous fluid41 in the sealing chamber 15 is raised. Therefore, the orificeresistance during the fluid movement in the gap (orifice) 24 becomeslarger, the residual vibration with the small amplitude is promptlydamped, as a result, there is no possibility of causing a reduction inthe riding comfort of the operator.

The vibration control mount apparatus 10 shown in FIG. 7 thus maintainslow viscosity of the electric viscous fluid 41 without changing itduring the initial pushing-up load based on a shock to absorb the loadThe viscosity variable controlling device 42 raises the viscosity of theelectric viscous fluid 41 during the residual vibration after the shock,and promptly damps the residual vibration based on inertia generatedafter the shock, without a large change to the conventional viscousmount shape, similarly to the vibration control mount apparatus 10 shownin FIG. 1. Accordingly, it is possible to plan improvements in thedurability of the cab 8 and the riding comfort of the operator, etc.Further, the vibration control mount apparatus 10 can change the orificeresistance in the gap (orifice) 24 by the electric viscous fluid 41 toenlarge the gap (orifice) 24 between the damper plate 23 and the casebody 11. Therefore, the apparatus 10 can control abrasion caused byinterference between the damper plate 23 and the case body 11, maintainthe stable damping factor characteristic, and make the secular change ofperformance smaller.

Moreover, in either embodiment, the acceleration detecting device 31 maybe an acceleration sensor which directly detects the vibrationacceleration of the movable body 21. Further, an elastic body supportingthe movable body 21 is not limited to the mount rubber 14, and may be anobject employing a spring, etc.

Furthermore, the vibration control mount apparatus 10 is applicable to atraveling machine such as a truck, in addition to the working machinesuch as the oil hydraulic power shovel 1.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a working machine such as an oilhydraulic power shovel or a traveling machine such as a truck.

1. A vibration control mount apparatus comprising: a case body mountedon a mount base member; an elastic body mounted on the case body; asealing chamber formed in the case body; a viscosity change fluid whichis sealed in the sealing chamber and of which viscosity is changed; amovable body that has a damper plate which moves while receivingresistance from the viscosity change fluid in the sealing chamber andthat is supported by the elastic body; acceleration detecting device fordetecting vibration acceleration of the movable body; and viscosityvariable controlling device for changing the viscosity of the viscositychange fluid in accordance with vibration acceleration detected by theacceleration detecting device.
 2. The vibration control mount apparatusaccording to claim 1, wherein the viscosity change fluid is a magneticviscous fluid of which viscosity is changed by a magnetic field; and theviscosity variable controlling device forms the magnetic field inaccordance with vibration acceleration detected by the accelerationdetecting device to change the viscosity of the magnetic viscous fluid.3. The vibration control mount apparatus according to claim 1, whereinthe viscosity change fluid is an electric viscous fluid of whichviscosity is changed by application of voltage; and the viscosityvariable controlling device applies voltage in accordance with vibrationacceleration detected by the acceleration detecting device to change theviscosity of the electric viscous fluid.
 4. The vibration control mountapparatus according to claim 1, wherein the viscosity variablecontrolling device raises viscosity of the viscosity change fluid duringresidual vibration generated by a shock.
 5. The vibration control mountapparatus according to claim 1, wherein the mount base member is aturning frame of a working machine; and a cab floor member is mounted onthe movable body.